1. Field of the Invention
The present invention relates to a four wheel drive system, particularly for a transverse engine layout.
2. Description of the Prior Art
An example of this kind four wheel drive system is disclosed in Japanese Provisional Patent Publication No. 58-63523. In this four wheel drive system, a final reduction gearing and a center differential are accommodated within a transaxle case while a front differential for front road wheels is accommodated within a supplementary case attached to the transaxle case on the same side thereof where an engine is attached to. By this, it is intended to utilize constituent parts of a two wheel drive system as many as possible for attaining a four wheel drive system having a center differential.
However, since the center differential is adapted to be installed within the transaxle case in place of the front differential, the space for arrangement thereof is limited, resulting in design restrictions of the center differential as for example a problem that a viscous clutch cannot be installed in the limited space.